Lung cancer is the most common cause of cancer death in adults. Yet, no real advances have been made in the evaluation of suspected lung-cancer patients since the development of flexible bronchoscopy in the early 1970's and CT scanning in the early 1980's. To improve the care of lung-cancer patients, this project seeks to devise and validate a computer-based system, the 3D Navigator, that ties together three-dimensional (3D)high-resolution computed tomographic (HRCT) imaging and bronchoscopy. The project is driven by the following hypothesis: A synergistic combination of 3D HRCT imaging, bronchoscopy, and image processing improves current procedures for HRCT-based lung- cancer assessment. Also, during bronchoscopy, this combination of tooLs permits more accurate assessment and higher biopsy yields. The 3D Navigator consists of a computer-based system that interfaces to a bronchoscope. It is used for initial HRCT assessment and concurrently during bronchoscopy. The system expands upon the new concept of virtual endoscopy: the physician interacts with the system's visual and quantitative tools to explore and evaluate, with impunity, the "virtual anatomy" embodied by a patient's 3D HRCT scan. When used during bronchoscopy, the 3D Navigator-gives the physician augmented vision, potentially increasing the likelihood of successful procedures. The women's Intervention Nutrition Study (WINS) is a prospective, randomized, multi-center clinical trIal testing the hypothesis that dietary fat intake reduction as an adjuvant to standard breast cancer therapy successful procedures. The project'S four specific aims are as follows. Aim 1: Construct the 3D Navigator system, including the maln software and bronchoscope interface. Aim 2: Devise automatic imageprocessing methods for 3D HRCT thoracic analysis; the methods, which assist the physician in CT assessment and bronchoscopy planning, focus on lesion/lymph-node detection, airway analysis, quantitation, and computation of "road maps" to suspect lesion sites. Aim 3: For CT-only assessment, validate the 3D Navigator versus standard human assessment. Aim 4: Validate the 3D Navigator when used concurrently with bronchoscopy. For aims 3 and 4, phantom, cadaver, and human studies are done; the impact of CT scanning protocol is also considered. In the long run, we believe that our combination of tools, as embodied in the 3D Navigator, will provide a more effective means for the early detection, staging, diagnosis, and treatment of lung cancer than the traditional approach using CT and bronchoscopy. It also could prove useful for general pulmonary disease assessment and treatment delivery. Finally, our proposed visual and quantitative methodology could have direct applicability to other endoscopic procedures such as mediastinoscopy, colonoscopy (colorectal cancer), and cystoscopy (bladder cancer).